Unraveling the Interfacial Charge Migration Pathway at the Atomic Level in a Highly Efficient Z-Scheme Photocatalyst

Pengfei Wang; Yueshuang Mao; Lina Li; Zhurui Shen; Xiao Luo; Kaifeng Wu; Pengfei An; Haitao Wang; Lina Su; Yi Li; Sihui Zhan

doi:10.1002/anie.201904571

Unraveling the Interfacial Charge Migration Pathway at the Atomic Level in a Highly Efficient Z-Scheme Photocatalyst

Angew Chem Int Ed Engl. 2019 Aug 12;58(33):11329-11334. doi: 10.1002/anie.201904571. Epub 2019 Jul 3.

Authors

Pengfei Wang¹, Yueshuang Mao¹, Lina Li², Zhurui Shen³, Xiao Luo⁴, Kaifeng Wu⁴, Pengfei An⁵, Haitao Wang¹, Lina Su¹, Yi Li⁶, Sihui Zhan¹

Affiliations

¹ MOE Key Laboratory of Pollution Processes and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, P. R. China.
² Shanghai Synchrotron Radiation Facility, Shanghai Advanced Research Institute, Shanghai, 201800, P. R. China.
³ School of Materials Science and Engineering, Nankai University, Tianjin, 300350, P. R. China.
⁴ State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, P. R. China.
⁵ Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, P. R. China.
⁶ Department of Chemistry, Tianjin University, Tianjin, 300072, P. R. China.

PMID: 31115145
DOI: 10.1002/anie.201904571

Abstract

A highly efficient Z-scheme photocatalytic system constructed with 1D CdS and 2D CoS₂ exhibited high photocatalytic hydrogen-evolution activity of 5.54 mmol h^-1 g^-1 with an apparent quantum efficiency of 10.2 % at 420 nm. More importantly, its interfacial charge migration pathway was unraveled: The electrons are efficiently transferred from CdS to CoS₂ through a transition atomic layer connected by Co-S_5.8 coordination, thus resulting in more photogenerated carriers participating in surface reactions. Furthermore, the charge-trapping and charge-transfer processes were investigated by transient absorption spectroscopy, which gave an estimated charge-separation yield of approximately 91.5 % and a charge-separated-state lifetime of approximately (5.2±0.5) ns in CdS/CoS₂ . This study elucidates the key role of interfacial atomic layers in heterojunctions and will facilitate the development of more efficient Z-scheme photocatalytic systems.

Keywords: charge migration; direct Z-scheme photocatalysts; heterojunctions; interfaces; photocatalysis.

Abstract

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